Electric-clock system



' A. F. POOLE. ELECTRIOCLOCK SYSTEM. APPLICATION FILED FEB-15, 1915- Patented July 15; 1919.

ARTHUR F. POOLE, OF CHICAGO, ILLINOIS.

ELECTRIC-CLOCK SYSTEM.

Specification of Letters Patent.

Patented J uly 15, 1919.

Application filed February 15, 1915. serial No. 8,196.

- T all whom it may concern;

ARTHUR F. POOLE,

- tures of-the electric'clock system described said application in my co-pending application Serial No. 861,360, filed September 12, 191%. In the of electric clocks suitable for use in connection with an electric light and power installation. The secondary clocks consist of synchronous motors connected to'the conductors used for the distribution of light and power, and the alternating-current generator at the central station is synchronized with a master clock, ary clocks will reproduce the time of the master clock. In said application, the master clock which serves to synchronize the generator is shown mechanically connected thereto. master clock being located at the central station.

. My present invention has ror its object the provision of means whereby the master clock will be located at any convenient locality, not necessarily at the central station, and the connection between the master clock and the alternating-current generator whereby the latter is synchronized is a purely electrical connection.- My improved arrangement which forms the subject of present invention thus has the advantage" that an ordinary clock may be used as the master clock and that this clock may be located away from the central station in a place not subject to the jar and vibration-necessarily present in a central station, thus enabling the master clock to keep much more accu rate time than otherwise.

My resent invention may be best understood y reference to the accompanying sheet of drawings, in which,

Figure 1 is a diagrammatic arrangementof the parts necessary to accomplish the results as above s t forth; and

States, residing at I have described a system.

whereby these second-s This arrangement necessitates the .relay 15 to move away Fig. 2 is a detail showing the connection of the worm wheel controlling the throttle, with the rod on which it is mounted.

Reference thereto will disclose at 1 a master clock, which may be of any suitable construction, and is provided with a contact to close an electric circuit periodically, which period, for the purposes of this present invention, may be taken as one second. Since clocks provided with mechanism of this kind are old in the art, it is not necessary to enter into a detailed description of the same.

The master clock 1 is connected by wires 2 and 3 to a relay 4, and through a pair of contacts 5 and 6 to a battery 7 which has one side connected to the ground 9. The relay 4 is provided with an armature 10, which is normally held against its back stop 11 by a retractile spring 12, and which when attracted by v with points 13 and 14. It must be borne in mind that the conductors 2 and 3 are connected to the contact in the master clock, which contact serves to close the circuit once every second. Therefore at every second, upon the closing of the circuit by the master clock, the armature 10 will be attracted by the relay 4 and contact with the 14 serves to tore once each second this armature 10 wili be drawn up, and remain up, even if the contacts in the master clock 1 are opened, until the contacts 5'and 6 are separated by means afterward to tion of these contacts 5 and 6 will of course open the circuit from the battery 7 and the armature 10 will thereupon be drawn against its back stop 11. From the contact 13 a circuit may be traced through the relay 15 to the ground rests against a contact .17. The fact of the described will cause the armature 16 of the from the contact 17, and the circuit controlled by the armature 16 and contact 17 will remain open as long 9. This relay 15 is provided with an armature 16 which normally the relay 4 serves to, contact 7 4 when its armature is atbe described. Separaas the armature of the relay 4 is main- @tained in" its front position.

* 18- is a diagrammatic representation of a shunt motor which is driven from the mains 19 and. 20.- .It is provided with a field coil 21' and an auxiliary resistance 22 infseries with said field coil. This motor 18is gearedby a worm 23 to'a worm" 'wheel 24 on ashaft 25, rigidly attached to which is an arm'26 which serves 'to open-the contacts 5 and 6 at-each revolution of the shaft .25. The W616 23 and wheel 24 areso proportioned that the shaft 25 revolves synchronously with the closing of the circuit by the master clock 1,that is, .in the present instance, the shaft 25 makes one revolution per second. The motor 18 is so arranged that when running under the influence 0fthe field coil 21 it runssomewhat slower than the normal rate; but when running under the influence of the field coil 21 with the auxiliary resistance 22 in. series there-.

with, it runs somewhat faster than the normal rate. It will be observed thatthe auxiliary resistance 22 is normally shunted by the armature 16 being'in contact with the point 17 Therefore as the armature 16 is periodically attracted by the current from the.

master clock, as just described, it is obvious that the motor 18 will run faster than the normal speed corresponding to the armature 16 being away from-the contact 17,- and slower than the normal speed corresponding to the armature 16 being in contact with the contact point 17.

It will be remembered that the master clock closes the circuit 2, 3 once each second,

7 and that in consequence thereof the'relay 15 attracts its armature 16 once each sec ond; also that when thisarmature 16 has been once attracted it will remain attracted until the arm '26 has separated the contacts 5 and 6. Now assume that in the normal running of theapparatus, just at the instant when the master clock closes the; cir-' cuit, the arm 26 is in the position shownby the dotted line 27.. The motor 18 will then be accelerated until the arm 26 breaks the contacts 5 and 6. From then on until the next ensuing current from the master clock the motor18 will be retarded, and when the arm 26 reaches the dotted line 27 again,the'

motor will be again accelerated. Assume that for any reason the motor 18 is retarded.

Then when the master clock 1 closes the circuit, the arm 26 will not have reached the position of the dotted line 27. Consequently the accelerated period of the motor 18 will last longer than normal. Therefore the average speed of the motor will be increased. To take the other case, assume that,

after the breaking of the contacts 5 and "6,

the arm 26 has reached a position ahead of the dotted line 27 when the master clock 1 next closes the circuit. Since the accelerated.

period of the motor 18 does not commence" until the relay 15 has pulled up its armature .16, it is obvious that in thiscase the accelerated period of the motor 18 will be shortened and the retarded period of the motor 18 will be lengthened; hence the average speed of the motor will be slower..

' As above described, the very fact of the average speed of the motor varying. from normal will" throw into operation circuit connections which tendt'o bring said speed back to normal again. It'is obvious that the average speed of the shaft '25 will be exgear 29 will make exactly the same number of revolutions as the bevel gear 28, except that it will make] these revolutions in the reverse direction. The generator 31 is connected to the bussbars 39 and 40, and these are connectedtto the synchronous motor 30, as shown. Mounted between the bevel gears 28 and 29 is a bevel gear 32 mounted'in a gear 33, the system of gears 28, 29, 32 and 33 forming an ordinary differential gear. Obviously, if the speed of the generator 31,

and consequently that of the synchronous \motor 30 running instep therewith, should \vary from the normal speed, the bevel gear 32 and the gear 33 in which the same is mounted will be displaced in one direction or the other. Meshingin the gear 33 is a gear 34 rigidly mounted on a'shaft 35, on which is a worm 36 meshing in a wheel 37 which is loosely mounted on the throttle shaft 41. A detail of this mounting is shown in Fig.2, from which it will be seen that,

the wheel 37 has in it a stop 43 which plays -between the ends of a 'i slot 44 in a cam 45 rigidly mounted on the throttle shaft 41, the object of this arrangement being to pro duce some lost motion between the wheel 37 and the throttle shaft 41, and thus pre-. vent hunting of the engine 38 while the same is being governed. The throttle 46 controls the admission of steam to the prime mover 38, which is belted to the alternating-current generator 31. The worm36 is so geared to the wheel 37 that in case the generator 31 runs faster than'the normal speed, as determined by the shaft 25, the gear 34 will be rotated in a direction to shut off the steam, thereby reducing the speed of the engine 38. In case the generator 3L runs admit more steam to. the

slower than the normal speed, consequent rotation of the gear 33, and with said gear the gears 34 and 36, will be in a direction to engine 38, and thereby increase its speed. a

The general plan of my present invention will be recognized as substantially that of the synchronizing apparatus for the. genera:

' time signals as sent tor shown in my co-pending application above referred to; the advantage of my present invention over the arrangement shown in my co-pending application being in the nature of permitting the master clock to be located at some suitable place not necessarily at the central station.

It is obvious that occasional failure of the master clock 1.to close the circuit will not interfere with the correct operation of my invention, since it is not necessary that the shaft 25 be corrected at every revolution. Correction may be omitted for three or four revolutions, or possibly longer, without said shaft gettin out of cycle. Attention is also directed to t e fact that the ordinary signals as sent out by an observatory maybe used to synchronize the generator 31, since, as above described,

2. In an electric-clock system: a master.

clock; a relay closed periodically thereby; a generator; and means to synchronize said generator with the periodic operations of said relay.

3. In an electric-clock system: amaster clock; means for sending out periodic cur- ,rents, said means being governed by said master clock; an alternating-current generator; and means for so synchronizing the said generator with the saidperiodic currents that the frequency of the generator will be constant"; 4:. In anelectric clock system, the combination of a master clock, a differential gear, means to control said'gear by said master clock, a throttle, means to control said throttle by said difierential gear, said means including a lost motion connection between said throttle and saiddifferential gear.

all that is necessary to synchronlze th1s generator 1s a source of cur- 5. The combination of a master clock, a, circuit periodically closed thereby a relay in this circuit, an aIternating current generator, and means whereby the generator is so controlled by the relay as to be actuated in synchronism with the master clock.

6. In a clock system, the combinationwith a master clock and an alternating-current generator, of a motor actuated in synchro- I nism with the clock, a second motor actuated 1n synchronism with the generator, and means connected between the motors for so controlling the generator that its average speed is constant.

7. In combination with a prime mover, a moving member operating at a predetermined speed relatively to the speed of the prime mover, and having a fixed relation thereto, a master clock, a second moving member mechanically independent of the master clock, and constructed and arranged to maintain an unvarying speed relation thereto, and mechanism controlling the speed of said prime mover dependent for itsoperation upon the relative movement of said moving members-to compensate for the revolutions gained or lost by said prime mover due to a variation in speed thereof.

8. In combination with a prime mover, a moving member operating at a predetermined speed relative to the speed of the prime mover and having a fixed relation thereto, amaster clock, a second moving member mechanically independent of the master clock and arranged to maintain an unvarying speed relation thereto, said moving members having a predetermined relation to each other so long as said prime mover maintains a normal rate of rotation, and mechanism depending for its operation jugpon the relation of said moving members to each other, said mechanism operating to vary said prime mover from normal speed whenever the average rate of rotation of the prime mover does not equal its normal rate of rotation, and continuing to vary the prime'mover in speed until-its average rate of rotation corresponds to its normal rate of rotation. 4

9. In combination,

amaster clock, a prime mover operating at a fixed relation to the said master clock so long asit maintains its normal speed, a moving member mechanically independent of and having an unalterable fixed speed relation to said master .clock, a second moving member having an unalterable fixed relation to said prime mover and having a predetermined relation to said first member so long as said prime mover maintains its normal speed, and a differential gear mechanism for influencing thespeed of said prime mover whenever'the relation between said moving members varies, and for continuingto influence the speed of said prime mover until the predetermined relation between said prime mover and said master clock is'restored.

10. In combination, a master clock, a PI'IIHGIIIOVGI', means mechanlcally independent of the prime mover to integratethe rev- I given time, may be held to a predetermined amount and thus maintain the average rate of revolution of said prime mover a constant.

' 11. In combination, a master clock, an

electric generator, means to integrate-the revolutions of said generator and means mechanically independent of said clock to synchronize said integrated revolutions with said master clock whereby the total revolutions of said electric generator in a given time, may be held to a predetermined amount and thus maintain the average rate of revolution of said electric generator a constant.

12. In combination, a master clock,'a generator of alternating electric current, means to integrate the revolutions of said generator and means electrically connected only to said clock to synchronize said integrated revolutions with said master clock whereby the total revolutions of said generatorelectric current in a given time, may be held to a predetermined amount and thus maintain the average rate of revolution of said generator a constant.

13. In combination, a master clock, a relay controlled thereby, an electric motor, a resistance in said motor circuit and means con-' trolled by said relay to periodically shunt said resistance in synchronism with said lay actuated in synchronism therewith, an

electric motor, a resistance inthefield of sald electric motor and c1rcu1t connections to shunt said resistance in synchronism with the actuation of said relay. j

15. The combination with, a master clock,

an electric motor, means to maintain said motor in synchronism with said clock, and an electric generator, of a second motor actuated in synchronism with said generator,

a differential gear mechanism disposed between the motors, a prime mover and means whereby-the difierential member of the gear mechanism controls the source ogwer.

whereby the periodic impulses cause the Witnesses generator to develop a frequency that is in synchronism with the cloc 17. In combination, a master clock, an electric motor, means to maintain said electric motor in synchronism withsaid master clock, a differential gear, one element of which is connected to said'electric motor, an electric generator, means to rotate a second element of 'said' difierential gear in synchronism with said electric generator, a prime mover and means to control the source of power for said prime mover, sald means being connected to the third element of said difierential gear. 0

18. In an electric clock system, the combination at a' master clock, an alternating current generator, light and powerconductors leading from said generator to a series of lamps and motors supplied with current over said conductors, a prime mover to drive I said alternating current generator, means to send out a series of currents periodically, said means being governedby said means to synchronize said generators with the periodic operations of said relay,

. master clock, and means to synchronize said whereby the average number of alternations sent out by'said generator in a given period of time may be accurately regulated.

20. In a clock system, the combination with a master clock and-an alternating-cure rent generator, of a motor actuated in synchronlsm with the clock, a second motor actuated in synchronism with the generator, and differential means connected betweenthe motors for socontrolling the generator thatits average frequencygis constant.

21Z In a clock system, the combination with a master clock and an alternating-cur.- rent generator, of a motor actuat'eel' in synchronism with the clock, a second motor actuated in synchronism with the generator, and differential means connected between the motors for so controlling the' generator that -.it maintains an average speed for any given period of time.

, In witness whereof I have hereunto signed my name this 13 day of Feb, 1915. a

' ARTHUR F. POOLE.

HYMAN ELI GOLDBERG, I. CHAIMOVITSCH. 

